130 



LANTERN WITH ALCOHOL LAMP AND MANTLE [Cn. V 



213. The management of an exhibition is as for the direct 

 current arc lamp, keeping in mind the general statements in this 

 chapter (Ch. I, 21-40; 193). 



THE MAGIC LANTERN WITH ALCOHOL LAMP AND MANTLE 



214. An alcohol flame burning in the air, is very hot. This 

 has been taken advantage of to heat a mantle to incandescence in 

 the same way that illuminating gas with a Bunsen burner heats a 

 mantle to incandescence. 



FIG. 72. MAGIC LANTERN WITH THE ALCO-RADIAXT. 

 (Cut loaned by Williams, Brown & Earle}. 

 For the details see fig. 32 and 73. 



For the best results the alcohol is vaporized, and the vapor burn- 

 ing in a special burner gives the Bunsen flame necessary to heat the 

 mantle. 



The light is as intense or more intense than gas light with a 

 mantle. 



215. Alcohol supply and burner. There must be a reservoir 



for alcohol (95% ethyl, methyl, or denatured). This is connected 

 with the burner by means of a metal tube with a stop-cock. In 

 use the reservoir is filled over half full, but must always have an 

 air space above. Connected with this air space is a force-pump 

 by which the alcohol is put under pressure. 



